EP1981196A1 - A passive optical network, equipment and method for supporting the multicast service - Google Patents

A passive optical network, equipment and method for supporting the multicast service Download PDF

Info

Publication number
EP1981196A1
EP1981196A1 EP07702163A EP07702163A EP1981196A1 EP 1981196 A1 EP1981196 A1 EP 1981196A1 EP 07702163 A EP07702163 A EP 07702163A EP 07702163 A EP07702163 A EP 07702163A EP 1981196 A1 EP1981196 A1 EP 1981196A1
Authority
EP
European Patent Office
Prior art keywords
optical
optical signal
demultiplexer
onu
multicast service
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP07702163A
Other languages
German (de)
French (fr)
Other versions
EP1981196B1 (en
EP1981196A4 (en
Inventor
Wei Huang
Huafeng Lin
Jun Zhao
Feng Wang
Tao Jiang
Jun Chen
Yuntao Wang
Guo Wei
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of EP1981196A1 publication Critical patent/EP1981196A1/en
Publication of EP1981196A4 publication Critical patent/EP1981196A4/en
Application granted granted Critical
Publication of EP1981196B1 publication Critical patent/EP1981196B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0226Fixed carrier allocation, e.g. according to service
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0227Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0228Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths
    • H04J14/023Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON]
    • H04J14/0232Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON] for downstream transmission
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0227Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0238Wavelength allocation for communications one-to-many, e.g. multicasting wavelengths
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0227Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0245Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for downstream transmission, e.g. optical line terminal [OLT] to ONU
    • H04J14/0246Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for downstream transmission, e.g. optical line terminal [OLT] to ONU using one wavelength per ONU
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0227Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0249Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU
    • H04J14/025Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0278WDM optical network architectures
    • H04J14/0282WDM tree architectures
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • H04J14/0227Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation

Definitions

  • the present invention relates to Passive Optical Network (PON) technology, and more particularly to a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) for supporting multicast service, an Optical Line Terminal (OLT) used in the WDM-PON, an Optical Network Unit (ONU), a multiplexer/demultiplexer, and a method for realizing multicast service using the WDM-PON.
  • PON Passive Optical Network
  • WDM-PON Wavelength Division Multiplexed Passive Optical Network
  • OLT Optical Line Terminal
  • ONU Optical Network Unit
  • multiplexer/demultiplexer a multiplexer/demultiplexer
  • the PON is a user access network that could meet the bandwidth requirements for the above high speed data service, which is cost-saved and convenient for operation and maintenance.
  • the PON mainly includes: an OLT located in the central office, an Optical Distribution Network (ODN) and multiple ONUs.
  • the ODN conventionally consists of a multiplexer/demultiplexer and fibers for connecting the multiplexer/demultiplexer with the OLT and ONUs.
  • the multiplexer/demultiplexer is configured to demultiplex an optical signal from the OLT and transmit demultiplexed optical signals to each of the ONUs respectively.
  • the multiplexer/demultiplexer is also configured to multiplex optical signals from each of the ONUs and output a multiplexed optical signal to the OLT.
  • the PON may be classified into a plurality of different types, such as, the Asynchronous Transfer Mode over PON (ATM-PON) which is based on ATM, the Ethernet over PON (EPON) which is based on Ethernet, the Gigabit PON (GPON) which has a rate of gigabits, the WDM-PON which is in combination with WDM technique, the Optical Code Division Multiple Access Passive Optical Network (OCDMA-PON) which is in combination with Code Division Multiple Access (CDMA) technique, etc.
  • ATM-PON Asynchronous Transfer Mode over PON
  • EPON Ethernet over PON
  • GPON Gigabit PON
  • WDM-PON which is in combination with WDM technique
  • OCDMA-PON Optical Code Division Multiple Access Passive Optical Network
  • the WDM-PON is of a point-to-point network structure.
  • a point-to-point network conventionally transmits multicast service data in a manner of multiple replication in-band.
  • high processing capability of the OLT is required, and a complex multicast protocol is necessary for supporting the multicast service.
  • the processing capability of the OLT becomes the bottleneck of the WDM-PON system.
  • the bandwidth resource of the system is wasted.
  • Embodiments of the present invention provide a WDM-PON which can save the bandwidth resource of the system and decrease the requirements for the processing capability of an OLT.
  • Embodiments of the present invention further provide an OLT, a multiplexer/demultiplexer and an ONU.
  • Embodiments of the present invention further provide a method for realizing the multicast service and cable TV (CATV) broadcasting, which can decrease the requirements for the processing capability of an OLT and save the bandwidth resource of a WDM-PON system greatly.
  • CATV cable TV
  • a WDM-PON includes an OLT, a multiplexer/demultiplexer and n ONUs.
  • the OLT is configured to carry downstream unicast data respectively transmitted to the n ONUs onto optical signals having different wavelengths, carry one or more channels of multicast service data respectively onto one or more optical signals having specific wavelengths, multiplex the optical signals having different wavelengths and the optical signals having specific wavelengths into one optical signal, and transmit the optical signal to the multiplexer/demultiplexer.
  • the multiplexer/demultiplexer is configured to divide the optical signals having different wavelengths from the OLT, perform power allocation on the optical signals having specific wavelengths for carrying the multicast service data, and wavelength-selectively output the optical signals carrying the downstream unicast data of the n ONUs.
  • the n ONUs are respectively configured to process the multicast service data outputted from the multiplexer/demultiplexer so as to obtain the multicast service data and their own downstream unicast data respectively.
  • An OLT includes an OLT downstream processing module, being configured to carry downstream unicast data, respectively transmitted to n ONUs, onto optical signals having different wavelengths, carry one or more channels of multicast service data respectively onto one or more specific optical signals with wavelengths, multiplex the optical signals having different wavelengths and the optical signals having specific wavelengths into one optical signal, and transmit the optical signal to a multiplexer/demultiplexer.
  • the multiplexer/demultiplexer includes a coarse wavelength demultiplexer, configured to divide a received optical signal into one or more channels of optical signals having specific wavelengths carrying the multicast service and optical signals for carrying downstream unicast data of each of the ONUs.
  • the multiplexer/demultiplexer further includes a 1: n AWG, being configured to divide the optical signals, which carry the downstream unicast data of each of the ONUs, from the coarse wavelength demultiplexer to obtain n channels of optical signals having different wavelengths, and route the optical signals having different wavelengths to n output terminals of the AWG respectively.
  • n AWG being configured to divide the optical signals, which carry the downstream unicast data of each of the ONUs, from the coarse wavelength demultiplexer to obtain n channels of optical signals having different wavelengths, and route the optical signals having different wavelengths to n output terminals of the AWG respectively.
  • the multiplexer/demultiplexer further includes a splitter with a splitting ratio of 1: a , being configured to perform power allocation on the optical signals having specific wavelengths from the coarse wavelength demultiplexer, split the power of the optical signals into a portions, and output the a portions of the split optical signals to a combiners respectively.
  • a splitter with a splitting ratio of 1: a being configured to perform power allocation on the optical signals having specific wavelengths from the coarse wavelength demultiplexer, split the power of the optical signals into a portions, and output the a portions of the split optical signals to a combiners respectively.
  • the multiplexer/demultiplexer further includes a combiners, each of which being connected to one output terminal of the AWG and one output terminal of the splitter, and being configured to couple the optical signals having specific wavelengths from the splitter to a output branches of the AWG.
  • n is a natural number
  • a is a natural number that is larger than 1 and less than or equal to n .
  • the ONU includes an ONU downstream processing module, which is configured to process the signal from the corresponding output terminal of the multiplexer/demultiplexer and obtain the downstream unicast data corresponding to the ONU itself and the multicast service data respectively.
  • a method for implementing multicast service in a WDM-PON system includes:
  • a method for realizing cable television (CATV) broadcasting in a WDM-PON network includes:
  • multicast service can be carried onto one or more optical signals having specific wavelengths, and thus the problem of the wasting of the bandwidth resource caused by the manner of in-band multiple replicas in the related art can be effectively solved, and the bandwidth resource of the system can be effectively saved. Moreover, because there is no need to support a complex multicast protocol in the OLT in the WDM-PON system, the complexity of the OLT can be reduced.
  • the quality of service of other real-time services can be ensured by separating multicast service to use a single wavelength for transmission, thereby the quality of service of the WDM-PON system can be ensured much better.
  • Fig.1 is a schematic diagram of the infrastructure of the current PON system
  • Fig.2 is a schematic diagram of the function of a multiplexer/demultiplexer used in a WDM-PON according to a preferred embodiment of the present invention
  • Fig.3 is a schematic diagram of the infrastructure of a WDM-PON according to a preferred embodiment of the present invention.
  • Fig.4 is a schematic diagram of the system structure for realizing multicast service in a WDM-PON according to another preferred embodiment of the present invention.
  • Fig.5 is a schematic diagram of the system structure for realizing CATV service and multicast service in a WDM-PON according to another preferred embodiment of the present invention
  • Fig.6 is a schematic diagram of the internal structure of a multiplexer/demultiplexer according to a preferred embodiment of the present invention.
  • Fig.7 is a schematic diagram of the internal structure of a multiplexer/demultiplexer according to another preferred embodiment of the present invention.
  • Fig.8 is a flowchart of a method for realizing multicast service according to a preferred embodiment of the present invention.
  • a preferred embodiment of the present invention provides a WDM-PON system for supporting multicast service, for example, a WDM-PON system for supporting multicast service and/or broadcast service and/or cable television (CATV) service.
  • Fig.3 shows the infrastructure of the WDM-PON system according to the embodiment.
  • the WDM-PON system mainly includes: an OLT, a multiplexer/demultiplexer, n ONUs and fibers connecting the OLT, the multiplexer/demultiplexer and the n ONUs, where n is a natural number.
  • the OLT is configured to carry n channels of downstream unicast data to be respectively transmitted to the n ONUs into n optical signals respectively having different wavelengths, carry one or more channels of multicast service data into one or more optical signals respectively having specific wavelengths, multiplex the optical signals respectively having different wavelengths and the optical signals having specific wavelengths into one optical signal, and output the one optical signal to the multiplexer/demultiplexer.
  • the OLT is configured to separate upstream optical signals from each of the ONUs, recover upstream data of each of the users after performing detection and demodulation on the upstream optical signals, and output the retrieved upstream data to a superior equipment.
  • the multiplexer/demultiplexer is configured to: separate the optical signals having different wavelengths received from the OLT; perform power allocation or power splitting on an optical signal having specific wavelength which carries multicast service, such as an optical signal having a wavelength of ⁇ m , that is, concurrently output the optical signal having specific wavelength through part or all of output terminals; and selectively outputting, according to wavelength, n channels of the optical signals having other wavelengths which carry downstream unicast data of each of the ONUs respectively, that is, output the optical signals of different wavelengths through predetermined corresponding output terminals respectively.
  • the multiplexer/demultiplexer is configured to multiplex n channels of upstream signals, which have different wavelengths and are from different ONUs respectively, to obtain an optical signal, and output the optical signal to the OLT.
  • an ONU In the downstream direction, an ONU is configured to process a signal from one of the output terminals of the multiplexer/demultiplexer to obtain the multicast service data and the downstream unicast data corresponding to the ONU respectively.
  • the ONU In the upstream direction, the ONU is configured to carry its upstream data onto an optical signal having predetermined wavelength, and output the optical signal to the multiplexer/demultiplexer.
  • the OLT further includes an OLT downstream processing module, an OLT upstream processing module and a first optical circulator.
  • the first optical circulator is connected to the OLT downstream processing module, the OLT upstream processing module and the multiplexer/demultiplexer, and is configured to output the downstream optical signal from the OLT downstream processing module to the multiplexer/demultiplexer, and output the upstream optical signal from the multiplexer/demultiplexer to the OLT upstream processing module.
  • the OLT downstream processing module includes a downstream data separator, configured to separate, from downstream service data, the multicast service data and n channels of downstream unicast data respectively transmitted to the n ONUs.
  • the OLT downstream processing module further includes a multicast service data transmission pre-processing module which is configured to receive broadcast data (for example, the CATV signal) from the superior equipment and/or multicast service data from the downstream data separator, and perform process and amplification on the broadcast data and/or multicast service data to obtain one or more optical signals having one or more specific wavelengths, which carry one or more channels of the multicast service data.
  • broadcast data for example, the CATV signal
  • process and amplification on the broadcast data and/or multicast service data to obtain one or more optical signals having one or more specific wavelengths, which carry one or more channels of the multicast service data.
  • the multicast service data transmission pre-processing module optically amplifies the optical signal from the superior equipment, which carries the broadcast data, directly by an optical amplifier. For the one or more channels of the multicast service data from the downstream data separator, the multicast service data transmission pre-processing module modulates the multicast service data into one or more optical signals having specific wavelengths, and performs related processes to the modulated optical signals. Accordingly, the multicast service data transmission pre-processing module further includes an optical amplifier for optically amplifying the broadcast data, and/or one or more lasers for generating optical signals having specific wavelengths, and one or more modulators for modulating the multicast service data into the optical signals having specific wavelengths. The functions of the lasers and the modulators could be implemented in a separate Direct Modulation Laser (DML).
  • DML Direct Modulation Laser
  • the OLT downstream processing module further includes a primary wide-spectrum laser source for generating a wide-spectrum optical signal.
  • the WDM-PON may further include an alternate wide-spectrum laser source for providing backup wide-spectrum optical signals when the primary wide-spectrum laser source fails.
  • the OLT downstream processing module further includes a first Array Waveguide Grating (AWG) which is configured to process a wide-spectrum optical signal outputted from the primary wide-spectrum laser source or backup wide-spectrum laser source to generate n channels of optical signals, each of which has respective wavelength among the wavelengths of ⁇ 1 ⁇ n , thus providing laser sources having different wavelengths for an optical modulator array.
  • AMG Array Waveguide Grating
  • the OLT downstream processing module further includes an optical modulator array including n modulators, which is configured to modulate the downstream unicast data corresponding to the n ONUs from the downstream data separator into the n channels of optical signals, which are outputted from the first AWG and have wavelengths of ⁇ 1 ⁇ n , respectively.
  • the OLT downstream processing module further includes a multiplexer.
  • the multiplexer is configured to multiplex the one or more optical signals having special wavelengths (for example, ⁇ m , ⁇ b and so on) and n channels of optical signals having the wavelengths of ⁇ 1 ⁇ n respectively, into an optical signal; and output the multiplexed optical signal to the first optical circulator.
  • the one or more optical signals having special wavelengths may carry the multicast service data; and the n channels of optical signals may carry the downstream unicast data of the n ONUs, respectively.
  • the multiplexer may be a coupler, an AWG or other multiplexing equipments.
  • the OLT upstream processing module includes a second AWG, which is configured to divide the upstream optical signal of the first optical circulator to obtain n channels of optical signals, which have wavelengths of ⁇ 1 ⁇ n respectively.
  • the OLT upstream processing module further includes a Photodiode or Photo Detector (PD) array, i.e., PD array.
  • PD array includes n PDs configured to convert one channel of upstream optical signal from the second AWG to an electrical signal respectively.
  • the OLT upstream processing module further includes a demodulator array.
  • the demodulator array consists of n demodulators, which are configured to demodulate electrical signals outputted from the Photodiode or PD array and recover the upstream data of each of the ONUs, respectively.
  • the ONU in the WDM-PON shown in Fig.3 includes an ONU downstream processing module, an ONU upstream processing module and a second optical circulator.
  • the second optical circulator is connected to the ONU upstream processing module, the ONU downstream processing module and the multiplexer/demultiplexer.
  • the second optical circulator is configured to output an upstream optical signal from the ONU upstream processing module to the multiplexer/demultiplexer, and output a downstream optical signal from the multiplexer/demultiplexer to the ONU downstream processing module.
  • the ONU downstream processing module includes a coarse wavelength demultiplexer.
  • the coarse wavelength demultiplexer is configured to divide an optical signal outputted from the multiplexer/demultiplexer to obtain the optical signals having different wavelengths.
  • the divided optical signals include an optical signal having a wavelength among ⁇ 1 ⁇ n and optical signals having specific wavelengths, such as ⁇ m and/or ⁇ b .
  • the optical signal having a wavelength among ⁇ 1 ⁇ n is used for carrying downstream unicast data corresponding to the ONU, and the optical signals having specific wavelengths are used for carrying multicast service.
  • the ONU downstream processing module further includes a PD array consisting of a plurality of PDs, the number of which is determined based on the number of multicast services. If x channels of multicast service are carried, the PD array may include x +1 PDs, in which, one of the PDs is configured to convert the optical signal carrying downstream unicast data corresponding to the ONU, among the optical signals having wavelengths of ⁇ 1 ⁇ n from the coarse wavelength demultiplexer, into an electrical signal, and another x PDs are respectively configured to convert the optical signals having specific wavelengths from the coarse wavelength demultiplexer, which carry channels of the multicast services, into electrical signals.
  • the ONU downstream processing module further includes a demodulator array consisting of a plurality of demodulators, the number of which corresponds to the number of the PDs in the PD array.
  • One of the demodulators is configured to demodulate the electrical signal carrying the downstream unicast data of the ONU to obtain the downstream unicast data of the ONU, and another demodulators are respectively configured to demodulate the electrical signals outputted from the PD array, which carry channels of the multicast service data, to obtain each channel of the multicast service data.
  • the ONU upstream processing module includes a modulator, which is configured to modulate the upstream data of the ONU into an optical signal.
  • the optical signal is necessary for the ONU to transmit the upstream data.
  • the optical signal may be either from the OLT or generated by the ONU itself. If the optical signal is generated by the ONU itself, the ONU upstream processing module needs to include a light source, as shown in Fig.3 .
  • a dynamic operating process for realizing multicast service by the WDM-PON is described, in combination with Fig.4 , through another preferred embodiment of the invention.
  • the process for realizing multicast service using the WDM-PON includes: multicast service data is firstly extracted from data stream from the superior equipment by the downstream data separator; the extracted multicast service data is modulated by the modulator into an optical signal having the wavelength of ⁇ m outputted from a specific wavelength laser; the modulated optical signal is amplified by an optical amplifier; and the amplified optical signal having the wavelength of ⁇ m , which carries the multicast service data, is multiplexed by the multiplexer with the n channels of optical signals, which have the wavelengths of ⁇ 1 ⁇ n respectively and carry the downstream unicast data of each of the ONUs respectively, so as to obtain a multiple-wavelength optical signal having the wavelengths of ⁇ 1 ⁇ n and ⁇ m ; and the multiple-wavelength optical signal is transmitted to the multiplexer/demultiplexer through the first optical circulator.
  • the above specific wavelength laser, modulator and optical amplifier constitute the multicast service data transmission pre-
  • the multiplexer/demultiplexer divides the received optical signal to obtain optical signals at different wavelengths, concurrently outputs the optical signal having the wavelength of ⁇ m , which carries the multicast service data, through n output terminals; and outputs the n channels of optical signals, which have the wavelengths of ⁇ 1 ⁇ n respectively and carry the downstream unicast data of each of the ONUs respectively, to corresponding output terminals, respectively.
  • the optical signal respectively outputted from each of the output terminals of the multiplexer/demultiplexer at least includes the optical signal having the wavelength of ⁇ m and one channel of optical signal among the optical signals having the wavelengths of ⁇ 1 ⁇ n .
  • the optical signal having the wavelength of ⁇ m carries the multicast service data; and the optical signals having the wavelengths of ⁇ 1 ⁇ n carry the downstream unicast data of each of the ONUs, respectively.
  • the optical signal outputted from the output terminal 1 includes two wavelengths of ⁇ 1 and ⁇ m
  • the optical signal outputted from the output terminal 2 includes two wavelengths of ⁇ 2 and ⁇ m
  • the optical signal outputted from the output terminal n includes two wavelengths of ⁇ n and ⁇ m .
  • output signals are transmitted to the n ONUs of the WDM-PON system respectively.
  • the ONU downstream processing module divides the optical signal from the multiplexer/demultiplexer to obtain the optical signal having the wavelength of ⁇ m, , which carries the multicast service data, and one channel of optical signal carrying the downstream unicast data of the ONU among the optical signals having the wavelengths of ⁇ 1 ⁇ n . After the two channels of optical signals are converted into electrical signals and further demodulated respectively, the multicast service data and the unicast data corresponding to the ONU itself could be obtained.
  • the OLT is capable of capturing a request for joining a multicast group from an ONU, and implementing the function of a multicast agent in which the OLT determines, according to the result of the authentication returned from an superior multicast server, whether the ONU has the right to receive data of the requested multicast group, and sends a multicast service control message to the ONU according to the result of the determination.
  • the ONU filters data of the multicast group, which is permitted by the OLT to be received by the ONU, according to the multicast service control message from the OLT, and discards data of the multicast group, which is not permitted by the OLT to be received by the ONU.
  • the data of the multicast group is transmitted to a subordinate equipment for further process.
  • the WDM-PON system shown in Fig.3 may further provide CATV service.
  • Fig.5 shows a schematic diagram of the system structure of a WDM-PON capable of concurrently providing CATV service and multicast service according to another preferred embodiment of the present invention.
  • the WDM-PON which provides CATV service and multicast service for the ONUs, is made the following improvements on the basis of the structure as shown in Fig.4 .
  • an optical amplifier for connecting the outputting terminal to the multiplexer is added to amplify an optical signal having the wavelength of ⁇ b , which carries a CATV signal from the outside.
  • the specific wavelength laser, the modulator, the optical amplifier connected to the modulator and the optical amplifier for amplifying the CATV signal constitute the multicast service data transmission pre-processing module shown in Fig.3 .
  • the multiplexer/demultiplexer in the downstream direction, the multiplexer/demultiplexer further performs power allocation on the optical signal having the specific wavelength, i.e., ⁇ b , which carries the CATV signal, among the optical signals from the OLT. That is, the optical signal with the specific wavelength of ⁇ b is concurrently outputted to each of the output terminals.
  • the optical signal outputted from each output terminal of the multiplexer/demultiplexer includes the optical signal with the wavelength of ⁇ m which carries the multicast data, the optical signal with the wavelength of ⁇ b which carries the CATV signal, and one channel of optical signal among the optical signals having the wavelengths of ⁇ 1 ⁇ n which carry the downstream unicast data of each of the ONUs.
  • the optical signal having the wavelength of ⁇ b which carries the CATV signal is divided by the coarse wavelength division multiplexer.
  • the PD array and the modulator array further include a PD and a modulator for performing optical/electrical conversion and demodulation to the optical signal having the wavelength of ⁇ b , which carries the CATV signal, so as to obtain the CATV data at each of the ONUs.
  • the OLT may realize controllable receipt of CATV service in a similar manner with that for realizing multicast service, such as by transmitting a broadcast control message.
  • the WDM-PON system may realize multicast or broadcast service. Further, because only one or more divided wavelengths are used for carrying one or more channels of the multicast service data in the above WDM-PON system, the problem in the related art that the number of replicas needs to be consistent with the number of users to whom the multicast service data is to be transmitted can be effectively avoided, thereby the bandwidth resource of the WDM-PON system can be greatly saved. Further, the load scheduled by the OLT can be reduced, and there is no need to support a complex multicast scheduling protocol in the OLT, thereby the complexity of the system is reduced.
  • the multiplexer/demultiplexer used in the present WDM-PON system is different from that used in the related WDM-PON system.
  • a novel multiplexer/demultiplexer is provided, which is used in the above WDM-PON system, has the function of an AWG, and is capable of broadcasting optical signals having some specific wavelengths.
  • Fig.6 shows the structure of such multiplexer/demultiplexer.
  • the multiplexer/demultiplexer in the present embodiment includes a coarse wavelength demultiplexer, which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m and/or other specific wavelengths) carrying the multicast service and optical signals carrying the downstream unicast data of each of the ONUs.
  • a coarse wavelength demultiplexer which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m and/or other specific wavelengths) carrying the multicast service and optical signals carrying the downstream unicast data of each of the ONUs.
  • the multiplexer/demultiplexer further includes a 1: n AWG, being configured to divide the optical signals with the wavelengths of ⁇ 1 ⁇ n from the coarse wavelength demultiplexer to obtain n channels of optical signals respectively having respective wavelength among the wavelengths of ⁇ 1 ⁇ n , and route the optical signals to the n output terminals of the AWG, where n corresponds to the number of the ONUs in the WDM-PON system.
  • the multiplexer/demultiplexer further includes a splitter having a splitting ratio of 1: n .
  • the splitter is configured to perform power allocation on the optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m and/or other specific wavelengths) from the coarse wavelength demultiplexer, split the power of the optical signals into n portions, and output the n portions of the split optical signals to n combiners respectively.
  • the multiplexer/demultiplexer further includes n combiners, each of which is connected to one output terminal of the AWG and one output terminal of the splitter, for coupling the optical signals having specific wavelengths from the splitter to each of the output branches of the AWG.
  • the functions of the coarse wavelength demultiplexer, the splitter and the combiners may be integrated into a separate AWG, and the multiplexer/demultiplexer may be realized with the coarse wavelength demultiplexer, the splitter, the combiners, a N:N Wavelength Grating Router (WGR), etc..
  • WGR Wavelength Grating Router
  • each of the n output terminals of the multiplexer/demultiplexer in Fig.6 includes the optical signals having specific wavelengths for carrying the multicast service.
  • some ONUs in the WDM-PON system may not support the multicast service, and thus it is not necessary to concurrently output the multicast service to all of the output terminals of the multiplexer/demultiplexer.
  • a simplified multiplexer/demultiplexer according to another preferred embodiment of the present invention is provided in Fig.7 .
  • the multiplexer/demultiplexer includes a coarse wavelength demultiplexer, which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m and/or other specific wavelengths) for carrying the multicast service and optical signals for carrying the downstream unicast data of each of the ONUs.
  • a coarse wavelength demultiplexer which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m and/or other specific wavelengths) for carrying the multicast service and optical signals for carrying the downstream unicast data of each of the ONUs.
  • the multiplexer/demultiplexer further includes a 1: n AWG, which is configured to divide the optical signals having the wavelengths of ⁇ 1 ⁇ n from the coarse wavelength demultiplexer to obtain n channels of optical signals respectively having respective wavelength among the wavelengths of ⁇ 1 ⁇ n , and route the optical signals to the n output terminals of the AWG, where n corresponds to the number of the ONUs in the WDM-PON system.
  • the multiplexer/demultiplexer further includes a splitter having a splitting ratio of 1: a .
  • the splitter is configured to perform power allocation on the optical signals having specific wavelengths (for example, ⁇ b and/or ⁇ m ) from the coarse wavelength demultiplexer, split the power of the optical signals into a portions, and output the a portions of the split optical signals to a combiners respectively, where a is a natural number that is larger than or equal to 1 and smaller than n and corresponds to the number of the ONUs supporting the multicast service in the WDM-PON system.
  • the multiplexer/demultiplexer further includes a combiners, each of which is connected to one output terminal of the AWG and one output terminal of the splitter, for coupling the optical signals having specific wavelengths from the splitter to a output branches of the AWG.
  • the above multiplexer/demultiplexer may concurrently transmit the optical signals carrying the multicast service to each ONU of the WDM-PON system by performing power allocation, it is possible to transmit multicast or broadcast data at a separate wavelength, thereby the bandwidth resource of the system can be greatly saved.
  • the method mainly includes the following steps.
  • Step A the OLT separates, from downstream data from the superior equipment, multicast service data and each channel of downstream unicast data to be transmitted to each of the ONUs in the WDM-PON system.
  • Step B the OLT carries the multicast service data onto an optical signal having specific wavelength, and carries the downstream unicast date of each of the ONUs onto an optical signal having predetermined downstream wavelength for each of the ONUs respectively.
  • Step C the optical signal having specific wavelength and the each channel of optical signal carrying the downstream unicast data of each of the ONUs are multiplexed and transmitted to the multiplexer/demultiplexer in the ONU.
  • Step D the multiplexer/demultiplexer separates, from the received optical signal, the optical signal having specific wavelength and each channel of optical signal carrying the downstream unicast data for each of the ONUs according to wavelength, outputs the optical signal having specific wavelength to all or parts of the ONUs, and outputs each channel of optical signal carrying the downstream unicast data of an ONU to the corresponding ONU.
  • Step E each of the ONUs in the WDM-PON system separates, from the received optical signal, the optical signal having specific wavelength and the optical signal carrying the downstream unicast data of the ONU itself, performing optical/electrical conversion and demodulation to both of the optical signals to obtain the multicast service data and the downstream unicast data of the ONU itself, and transmits the multicast service data to the lower equipment for further process.
  • the OLT can control whether an ONU can receive the multicast service data, by transmitting a corresponding control message to the ONU.
  • the multicast service may be general multicast service, broadcast service, or CATV service.
  • CATV service the OLT transmits a broadcast control message to the ONU to prohibit the ONU from receiving the CATV broadcast signal or permit the ONU to receive the CATV broadcast signal.
  • the ONU After receiving the broadcast control message, if the broadcast control message prohibits the ONU from receiving the CATV broadcast signal, the ONU turns off an optical/electrical converter so as not to receive the CATV broadcast signal, and if the broadcast control message permits the ONU to receive the CATV broadcast signal, the ONU turns on the optical/electrical converter so as to receive the CATV broadcast signal.
  • the multicast or broadcast can be realized in the WDM-PON system. Because the multicast service is only transmitted once at a specific wavelength in the WDM-PON system, the problem of the wasting of the bandwidth resource caused by the manner of bandwidth multiple replicas in the related art can be solved.
  • the bandwidth resource of the system can be greatly saved, and the complexity of the OLT can be reduced for there is no need to apply a complex multicast protocol in the OLT.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)

Abstract

A Wavelength Division Multiplexed Passive Optical Network (WDM-PON), an Optical Line Terminal, an Optical Network Unit, a multiplexer/demultiplexer, and a method for realizing multicast service in the WDM-PON are disclosed. The WDM-PON and the method for realizing multicast service according to the present invention can transmit multicast service to be multicasted or broadcasted using a single wavelength, and thus the bandwidth resource of the system can be effectively saved and complexity of the system can be reduced.

Description

    FIELD OF THE INVENTION
  • The present invention relates to Passive Optical Network (PON) technology, and more particularly to a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) for supporting multicast service, an Optical Line Terminal (OLT) used in the WDM-PON, an Optical Network Unit (ONU), a multiplexer/demultiplexer, and a method for realizing multicast service using the WDM-PON.
  • BACKGROUND
  • With the development of high speed data service, such as video information service with high quality, Video on Demand (VoD), etc., users' requirements for data access bandwidth of an access network is up to about 100Mbps. The current access manners, such as dial-up, Asymmetrical Digital Subscriber Loop (ADSL), etc., could not meet the users' bandwidth requirements, therefore the demand for constructing an access network with fibers increases quickly. The PON is a user access network that could meet the bandwidth requirements for the above high speed data service, which is cost-saved and convenient for operation and maintenance.
  • The infrastructure of the current PON is shown in Fig.1. Generally, the PON mainly includes: an OLT located in the central office, an Optical Distribution Network (ODN) and multiple ONUs. The ODN conventionally consists of a multiplexer/demultiplexer and fibers for connecting the multiplexer/demultiplexer with the OLT and ONUs. The multiplexer/demultiplexer is configured to demultiplex an optical signal from the OLT and transmit demultiplexed optical signals to each of the ONUs respectively. The multiplexer/demultiplexer is also configured to multiplex optical signals from each of the ONUs and output a multiplexed optical signal to the OLT.
  • According to different realization mechanisms, the PON may be classified into a plurality of different types, such as, the Asynchronous Transfer Mode over PON (ATM-PON) which is based on ATM, the Ethernet over PON (EPON) which is based on Ethernet, the Gigabit PON (GPON) which has a rate of gigabits, the WDM-PON which is in combination with WDM technique, the Optical Code Division Multiple Access Passive Optical Network (OCDMA-PON) which is in combination with Code Division Multiple Access (CDMA) technique, etc..
  • The WDM-PON is of a point-to-point network structure. A point-to-point network conventionally transmits multicast service data in a manner of multiple replication in-band. On one hand, high processing capability of the OLT is required, and a complex multicast protocol is necessary for supporting the multicast service. Particularly, when the same program is demanded by many users, the processing capability of the OLT becomes the bottleneck of the WDM-PON system. On the other hand, because the same data needs to be replicated respectively at different wavelengths so as to be transmitted to different ONUs, the bandwidth resource of the system is wasted.
  • SUMMARY
  • Embodiments of the present invention provide a WDM-PON which can save the bandwidth resource of the system and decrease the requirements for the processing capability of an OLT.
  • Embodiments of the present invention further provide an OLT, a multiplexer/demultiplexer and an ONU.
  • Embodiments of the present invention further provide a method for realizing the multicast service and cable TV (CATV) broadcasting, which can decrease the requirements for the processing capability of an OLT and save the bandwidth resource of a WDM-PON system greatly.
  • A WDM-PON includes an OLT, a multiplexer/demultiplexer and n ONUs.
  • The OLT is configured to carry downstream unicast data respectively transmitted to the n ONUs onto optical signals having different wavelengths, carry one or more channels of multicast service data respectively onto one or more optical signals having specific wavelengths, multiplex the optical signals having different wavelengths and the optical signals having specific wavelengths into one optical signal, and transmit the optical signal to the multiplexer/demultiplexer.
  • The multiplexer/demultiplexer is configured to divide the optical signals having different wavelengths from the OLT, perform power allocation on the optical signals having specific wavelengths for carrying the multicast service data, and wavelength-selectively output the optical signals carrying the downstream unicast data of the n ONUs.
  • The n ONUs are respectively configured to process the multicast service data outputted from the multiplexer/demultiplexer so as to obtain the multicast service data and their own downstream unicast data respectively.
  • An OLT includes an OLT downstream processing module, being configured to carry downstream unicast data, respectively transmitted to n ONUs, onto optical signals having different wavelengths, carry one or more channels of multicast service data respectively onto one or more specific optical signals with wavelengths, multiplex the optical signals having different wavelengths and the optical signals having specific wavelengths into one optical signal, and transmit the optical signal to a multiplexer/demultiplexer.
  • The multiplexer/demultiplexer according to an embodiment of the present invention includes a coarse wavelength demultiplexer, configured to divide a received optical signal into one or more channels of optical signals having specific wavelengths carrying the multicast service and optical signals for carrying downstream unicast data of each of the ONUs.
  • The multiplexer/demultiplexer further includes a 1:n AWG, being configured to divide the optical signals, which carry the downstream unicast data of each of the ONUs, from the coarse wavelength demultiplexer to obtain n channels of optical signals having different wavelengths, and route the optical signals having different wavelengths to n output terminals of the AWG respectively.
  • The multiplexer/demultiplexer further includes a splitter with a splitting ratio of 1: a, being configured to perform power allocation on the optical signals having specific wavelengths from the coarse wavelength demultiplexer, split the power of the optical signals into a portions, and output the a portions of the split optical signals to a combiners respectively.
  • The multiplexer/demultiplexer further includes a combiners, each of which being connected to one output terminal of the AWG and one output terminal of the splitter, and being configured to couple the optical signals having specific wavelengths from the splitter to a output branches of the AWG.
  • n is a natural number, and a is a natural number that is larger than 1 and less than or equal to n.
  • The ONU according to an embodiment of the present invention includes an ONU downstream processing module, which is configured to process the signal from the corresponding output terminal of the multiplexer/demultiplexer and obtain the downstream unicast data corresponding to the ONU itself and the multicast service data respectively.
  • A method for implementing multicast service in a WDM-PON system includes:
    • an OLT separating, from downstream data of an superior equipment, multicast service data and each channel of downstream unicast data transmitted to at least one ONU;
    • the OLT carrying the multicast service data onto an optical signal with specific wavelength and carrying the downstream unicast data of at least one ONU onto at least one optical signal having predetermined wavelengths;
    • the OLT multiplexing the optical signal with specific wavelength and the at least one optical signal carrying the downstream unicast data of each of the ONUs, and transmitting the multiplexed signal to the multiplexer/demultiplexer;
    • the multiplexer/demultiplexer separating, from a received optical signal, the optical signal having specific wavelength carrying the multicast service data and the at least one optical signal carrying the downstream unicast data of each of the ONUs according to wavelengths, outputting the optical signal with specific wavelength carrying the multicast service data to part or all of the at least one ONUs, and outputting the at least one optical signals carrying the downstream unicast data of the ONUs respectively to the corresponding ONUs; and
    • the ONUs separating, from the received optical signals, the optical signal having specific wavelength carrying the multicast service data and their own optical signals carrying the downstream unicast data respectively, obtaining, after performing optical/electrical conversion and demodulation on both of the optical signals, the multicast service data and their own downstream unicast data, and transmitting the multicast service data to the lower stage equipment for further process.
  • A method for realizing cable television (CATV) broadcasting in a WDM-PON network includes:
    • an OLT receiving an optical signal having specific wavelength, which carries a CATV broadcast signal, from an superior equipment;
    • the OLT amplifying the received optical signal having specific wavelength carrying the CATV broadcast signal, through an optical amplifier;
    • the OLT multiplexing the optical signal having specific wavelength carrying the CATV broadcast signal, which has been optically amplified, and optical signals carrying downstream unicast data of each of ONUs, and transmitting the multiplexed signal to a multiplexer/demultiplexer;
    • the multiplexer/demultiplexer separating, from a received optical signal, the optical signal having specific wavelength carrying the CATV broadcast signal and the at least one optical signal carrying the downstream unicast data of each of the ONUs according to wavelength, concurrently outputting the optical signal with specific wavelength carrying the CATV broadcast signal to part or all of the ONUs, and outputting the at least one optical signal carrying the downstream unicast data of each of the ONUs to corresponding ONUs respectively; and
    • the ONUs separating, from the received optical signals, the optical signal with specific wavelength carrying the CATV broadcast signal and the optical signals carrying their own downstream unicast data, obtaining an electrical CATV broadcast signal after performing optical/electrical conversion on the optical signal with specific wavelength carrying the CATV broadcast signal, and transmitting the electrical signal to a lower stage equipment for further process, meanwhile, obtaining their own downstream unicast data after performing optical/electrical conversion on the optical signals carrying their own downstream unicast data, and transmitting the electrical signals to a lower stage equipment for further process.
  • It can be seen from the above that, in the WDM-PON system according to the embodiments of the present invention and in the process for realizing multicast service according to the method of the embodiments of the present invention, multicast service can be carried onto one or more optical signals having specific wavelengths, and thus the problem of the wasting of the bandwidth resource caused by the manner of in-band multiple replicas in the related art can be effectively solved, and the bandwidth resource of the system can be effectively saved. Moreover, because there is no need to support a complex multicast protocol in the OLT in the WDM-PON system, the complexity of the OLT can be reduced.
  • Furthermore, because, conventionally, the traffic of multicast service is large and its priority is high, the quality of service of other real-time services (for example, VOIP) can be ensured by separating multicast service to use a single wavelength for transmission, thereby the quality of service of the WDM-PON system can be ensured much better.
  • BRIEF DESCRIPTION OF THE DRAWING(S)
  • Fig.1 is a schematic diagram of the infrastructure of the current PON system;
  • Fig.2 is a schematic diagram of the function of a multiplexer/demultiplexer used in a WDM-PON according to a preferred embodiment of the present invention;
  • Fig.3 is a schematic diagram of the infrastructure of a WDM-PON according to a preferred embodiment of the present invention;
  • Fig.4 is a schematic diagram of the system structure for realizing multicast service in a WDM-PON according to another preferred embodiment of the present invention;
  • Fig.5 is a schematic diagram of the system structure for realizing CATV service and multicast service in a WDM-PON according to another preferred embodiment of the present invention;
  • Fig.6 is a schematic diagram of the internal structure of a multiplexer/demultiplexer according to a preferred embodiment of the present invention;
  • Fig.7 is a schematic diagram of the internal structure of a multiplexer/demultiplexer according to another preferred embodiment of the present invention; and
  • Fig.8 is a flowchart of a method for realizing multicast service according to a preferred embodiment of the present invention.
  • DETAILED DESCRIPTION
  • In order to clarify the objects, technical solutions and advantages of the present invention, detailed descriptions to the embodiments of the present invention are provided below with reference to the accompanying drawings.
  • A preferred embodiment of the present invention provides a WDM-PON system for supporting multicast service, for example, a WDM-PON system for supporting multicast service and/or broadcast service and/or cable television (CATV) service. Fig.3 shows the infrastructure of the WDM-PON system according to the embodiment. As shown in Fig.3, the WDM-PON system mainly includes: an OLT, a multiplexer/demultiplexer, n ONUs and fibers connecting the OLT, the multiplexer/demultiplexer and the n ONUs, where n is a natural number.
  • In the downstream direction, the OLT is configured to carry n channels of downstream unicast data to be respectively transmitted to the n ONUs into n optical signals respectively having different wavelengths, carry one or more channels of multicast service data into one or more optical signals respectively having specific wavelengths, multiplex the optical signals respectively having different wavelengths and the optical signals having specific wavelengths into one optical signal, and output the one optical signal to the multiplexer/demultiplexer. In the upstream direction, the OLT is configured to separate upstream optical signals from each of the ONUs, recover upstream data of each of the users after performing detection and demodulation on the upstream optical signals, and output the retrieved upstream data to a superior equipment.
  • The function of the multiplexer/demultiplexer is shown in Fig.2. In the downstream direction, the multiplexer/demultiplexer is configured to: separate the optical signals having different wavelengths received from the OLT; perform power allocation or power splitting on an optical signal having specific wavelength which carries multicast service, such as an optical signal having a wavelength of λm, that is, concurrently output the optical signal having specific wavelength through part or all of output terminals; and selectively outputting, according to wavelength, n channels of the optical signals having other wavelengths which carry downstream unicast data of each of the ONUs respectively, that is, output the optical signals of different wavelengths through predetermined corresponding output terminals respectively. In the upstream direction, the multiplexer/demultiplexer is configured to multiplex n channels of upstream signals, which have different wavelengths and are from different ONUs respectively, to obtain an optical signal, and output the optical signal to the OLT.
  • In the downstream direction, an ONU is configured to process a signal from one of the output terminals of the multiplexer/demultiplexer to obtain the multicast service data and the downstream unicast data corresponding to the ONU respectively. In the upstream direction, the ONU is configured to carry its upstream data onto an optical signal having predetermined wavelength, and output the optical signal to the multiplexer/demultiplexer.
  • Still referring to Fig.3, the OLT further includes an OLT downstream processing module, an OLT upstream processing module and a first optical circulator.
  • The first optical circulator is connected to the OLT downstream processing module, the OLT upstream processing module and the multiplexer/demultiplexer, and is configured to output the downstream optical signal from the OLT downstream processing module to the multiplexer/demultiplexer, and output the upstream optical signal from the multiplexer/demultiplexer to the OLT upstream processing module.
  • The OLT downstream processing module includes a downstream data separator, configured to separate, from downstream service data, the multicast service data and n channels of downstream unicast data respectively transmitted to the n ONUs.
  • The OLT downstream processing module further includes a multicast service data transmission pre-processing module which is configured to receive broadcast data (for example, the CATV signal) from the superior equipment and/or multicast service data from the downstream data separator, and perform process and amplification on the broadcast data and/or multicast service data to obtain one or more optical signals having one or more specific wavelengths, which carry one or more channels of the multicast service data.
  • The multicast service data transmission pre-processing module optically amplifies the optical signal from the superior equipment, which carries the broadcast data, directly by an optical amplifier. For the one or more channels of the multicast service data from the downstream data separator, the multicast service data transmission pre-processing module modulates the multicast service data into one or more optical signals having specific wavelengths, and performs related processes to the modulated optical signals. Accordingly, the multicast service data transmission pre-processing module further includes an optical amplifier for optically amplifying the broadcast data, and/or one or more lasers for generating optical signals having specific wavelengths, and one or more modulators for modulating the multicast service data into the optical signals having specific wavelengths. The functions of the lasers and the modulators could be implemented in a separate Direct Modulation Laser (DML).
  • The OLT downstream processing module further includes a primary wide-spectrum laser source for generating a wide-spectrum optical signal.
  • To ensure the reliability of the system, the WDM-PON may further include an alternate wide-spectrum laser source for providing backup wide-spectrum optical signals when the primary wide-spectrum laser source fails.
  • The OLT downstream processing module further includes a first Array Waveguide Grating (AWG) which is configured to process a wide-spectrum optical signal outputted from the primary wide-spectrum laser source or backup wide-spectrum laser source to generate n channels of optical signals, each of which has respective wavelength among the wavelengths of λ1∼λn, thus providing laser sources having different wavelengths for an optical modulator array.
  • The OLT downstream processing module further includes an optical modulator array including n modulators, which is configured to modulate the downstream unicast data corresponding to the n ONUs from the downstream data separator into the n channels of optical signals, which are outputted from the first AWG and have wavelengths of λ1∼λn, respectively.
  • The OLT downstream processing module further includes a multiplexer. The multiplexer is configured to multiplex the one or more optical signals having special wavelengths (for example, λm, λb and so on) and n channels of optical signals having the wavelengths of λ1∼λn respectively, into an optical signal; and output the multiplexed optical signal to the first optical circulator. The one or more optical signals having special wavelengths (for example, λm, λb and so on) may carry the multicast service data; and the n channels of optical signals may carry the downstream unicast data of the n ONUs, respectively. The multiplexer may be a coupler, an AWG or other multiplexing equipments.
  • The OLT upstream processing module includes a second AWG, which is configured to divide the upstream optical signal of the first optical circulator to obtain n channels of optical signals, which have wavelengths of λ1∼λn respectively.
  • The OLT upstream processing module further includes a Photodiode or Photo Detector (PD) array, i.e., PD array. The PD array includes n PDs configured to convert one channel of upstream optical signal from the second AWG to an electrical signal respectively.
  • The OLT upstream processing module further includes a demodulator array. The demodulator array consists of n demodulators, which are configured to demodulate electrical signals outputted from the Photodiode or PD array and recover the upstream data of each of the ONUs, respectively.
  • The ONU in the WDM-PON shown in Fig.3 includes an ONU downstream processing module, an ONU upstream processing module and a second optical circulator.
  • The second optical circulator is connected to the ONU upstream processing module, the ONU downstream processing module and the multiplexer/demultiplexer. The second optical circulator is configured to output an upstream optical signal from the ONU upstream processing module to the multiplexer/demultiplexer, and output a downstream optical signal from the multiplexer/demultiplexer to the ONU downstream processing module.
  • The ONU downstream processing module includes a coarse wavelength demultiplexer. The coarse wavelength demultiplexer is configured to divide an optical signal outputted from the multiplexer/demultiplexer to obtain the optical signals having different wavelengths. The divided optical signals include an optical signal having a wavelength among λ1∼λn and optical signals having specific wavelengths, such as λm and/or λb. The optical signal having a wavelength among λ1∼λn is used for carrying downstream unicast data corresponding to the ONU, and the optical signals having specific wavelengths are used for carrying multicast service.
  • The ONU downstream processing module further includes a PD array consisting of a plurality of PDs, the number of which is determined based on the number of multicast services. If x channels of multicast service are carried, the PD array may include x+1 PDs, in which, one of the PDs is configured to convert the optical signal carrying downstream unicast data corresponding to the ONU, among the optical signals having wavelengths of λ1∼λn from the coarse wavelength demultiplexer, into an electrical signal, and another x PDs are respectively configured to convert the optical signals having specific wavelengths from the coarse wavelength demultiplexer, which carry channels of the multicast services, into electrical signals.
  • The ONU downstream processing module further includes a demodulator array consisting of a plurality of demodulators, the number of which corresponds to the number of the PDs in the PD array. One of the demodulators is configured to demodulate the electrical signal carrying the downstream unicast data of the ONU to obtain the downstream unicast data of the ONU, and another demodulators are respectively configured to demodulate the electrical signals outputted from the PD array, which carry channels of the multicast service data, to obtain each channel of the multicast service data.
  • The ONU upstream processing module includes a modulator, which is configured to modulate the upstream data of the ONU into an optical signal.
  • The optical signal is necessary for the ONU to transmit the upstream data. The optical signal may be either from the OLT or generated by the ONU itself. If the optical signal is generated by the ONU itself, the ONU upstream processing module needs to include a light source, as shown in Fig.3.
  • A dynamic operating process for realizing multicast service by the WDM-PON is described, in combination with Fig.4, through another preferred embodiment of the invention.
  • As shown in Fig.4, in the OLT, the process for realizing multicast service using the WDM-PON includes: multicast service data is firstly extracted from data stream from the superior equipment by the downstream data separator; the extracted multicast service data is modulated by the modulator into an optical signal having the wavelength of λm outputted from a specific wavelength laser; the modulated optical signal is amplified by an optical amplifier; and the amplified optical signal having the wavelength of λm, which carries the multicast service data, is multiplexed by the multiplexer with the n channels of optical signals, which have the wavelengths of λ1∼λn respectively and carry the downstream unicast data of each of the ONUs respectively, so as to obtain a multiple-wavelength optical signal having the wavelengths of λ1∼λn and λm; and the multiple-wavelength optical signal is transmitted to the multiplexer/demultiplexer through the first optical circulator. The above specific wavelength laser, modulator and optical amplifier constitute the multicast service data transmission pre-processing module shown in Fig.3.
  • The multiplexer/demultiplexer divides the received optical signal to obtain optical signals at different wavelengths, concurrently outputs the optical signal having the wavelength of λm, which carries the multicast service data, through n output terminals; and outputs the n channels of optical signals, which have the wavelengths of λ1∼λn respectively and carry the downstream unicast data of each of the ONUs respectively, to corresponding output terminals, respectively. As such, the optical signal respectively outputted from each of the output terminals of the multiplexer/demultiplexer at least includes the optical signal having the wavelength of λm and one channel of optical signal among the optical signals having the wavelengths of λ1∼λn. The optical signal having the wavelength of λm carries the multicast service data; and the optical signals having the wavelengths of λ1∼λn carry the downstream unicast data of each of the ONUs, respectively. For example, the optical signal outputted from the output terminal 1 includes two wavelengths of λ1 and λm, the optical signal outputted from the output terminal 2 includes two wavelengths of λ2 and λm, ..., and the optical signal outputted from the output terminal n includes two wavelengths of λn and λm. Subsequently, then output signals are transmitted to the n ONUs of the WDM-PON system respectively.
  • In each of the ONUs, the ONU downstream processing module divides the optical signal from the multiplexer/demultiplexer to obtain the optical signal having the wavelength of λm,, which carries the multicast service data, and one channel of optical signal carrying the downstream unicast data of the ONU among the optical signals having the wavelengths of λ1∼λn. After the two channels of optical signals are converted into electrical signals and further demodulated respectively, the multicast service data and the unicast data corresponding to the ONU itself could be obtained.
  • Meanwhile, in order to realize the multicast service, the OLT is capable of capturing a request for joining a multicast group from an ONU, and implementing the function of a multicast agent in which the OLT determines, according to the result of the authentication returned from an superior multicast server, whether the ONU has the right to receive data of the requested multicast group, and sends a multicast service control message to the ONU according to the result of the determination. The ONU filters data of the multicast group, which is permitted by the OLT to be received by the ONU, according to the multicast service control message from the OLT, and discards data of the multicast group, which is not permitted by the OLT to be received by the ONU. After the ONU filters the data of the multicast group permitted by the OLT, the data of the multicast group is transmitted to a subordinate equipment for further process.
  • The WDM-PON system shown in Fig.3 may further provide CATV service. Fig.5 shows a schematic diagram of the system structure of a WDM-PON capable of concurrently providing CATV service and multicast service according to another preferred embodiment of the present invention.
  • As shown in Fig.5, the WDM-PON, which provides CATV service and multicast service for the ONUs, is made the following improvements on the basis of the structure as shown in Fig.4.
  • For the OLT, an optical amplifier for connecting the outputting terminal to the multiplexer is added to amplify an optical signal having the wavelength of λb, which carries a CATV signal from the outside. As shown in Fig.5, the specific wavelength laser, the modulator, the optical amplifier connected to the modulator and the optical amplifier for amplifying the CATV signal constitute the multicast service data transmission pre-processing module shown in Fig.3.
  • For the multiplexer/demultiplexer, in the downstream direction, the multiplexer/demultiplexer further performs power allocation on the optical signal having the specific wavelength, i.e., λb, which carries the CATV signal, among the optical signals from the OLT. That is, the optical signal with the specific wavelength of λb is concurrently outputted to each of the output terminals. As such, the optical signal outputted from each output terminal of the multiplexer/demultiplexer includes the optical signal with the wavelength of λm which carries the multicast data, the optical signal with the wavelength of λb which carries the CATV signal, and one channel of optical signal among the optical signals having the wavelengths of λ1∼λn which carry the downstream unicast data of each of the ONUs.
  • Furthermore, for the ONU, the optical signal having the wavelength of λb which carries the CATV signal is divided by the coarse wavelength division multiplexer. The PD array and the modulator array further include a PD and a modulator for performing optical/electrical conversion and demodulation to the optical signal having the wavelength of λb, which carries the CATV signal, so as to obtain the CATV data at each of the ONUs.
  • In the process for realizing CATV service, the OLT may realize controllable receipt of CATV service in a similar manner with that for realizing multicast service, such as by transmitting a broadcast control message.
  • It can be seen from the above process for realizing multicast service, the WDM-PON system may realize multicast or broadcast service. Further, because only one or more divided wavelengths are used for carrying one or more channels of the multicast service data in the above WDM-PON system, the problem in the related art that the number of replicas needs to be consistent with the number of users to whom the multicast service data is to be transmitted can be effectively avoided, thereby the bandwidth resource of the WDM-PON system can be greatly saved. Further, the load scheduled by the OLT can be reduced, and there is no need to support a complex multicast scheduling protocol in the OLT, thereby the complexity of the system is reduced.
  • It can be seen from the above embodiments that the multiplexer/demultiplexer used in the present WDM-PON system is different from that used in the related WDM-PON system. In order to realize the present WDM-PON system, in a preferred embodiment of the present invention, a novel multiplexer/demultiplexer is provided, which is used in the above WDM-PON system, has the function of an AWG, and is capable of broadcasting optical signals having some specific wavelengths. Fig.6 shows the structure of such multiplexer/demultiplexer.
  • As shown in Fig.6, the multiplexer/demultiplexer in the present embodiment includes a coarse wavelength demultiplexer, which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, λb and/or λm and/or other specific wavelengths) carrying the multicast service and optical signals carrying the downstream unicast data of each of the ONUs.
  • The multiplexer/demultiplexer further includes a 1:n AWG, being configured to divide the optical signals with the wavelengths of λ1∼λn from the coarse wavelength demultiplexer to obtain n channels of optical signals respectively having respective wavelength among the wavelengths of λ1∼λn, and route the optical signals to the n output terminals of the AWG, where n corresponds to the number of the ONUs in the WDM-PON system.
  • The multiplexer/demultiplexer further includes a splitter having a splitting ratio of 1:n. The splitter is configured to perform power allocation on the optical signals having specific wavelengths (for example, λb and/or λm and/or other specific wavelengths) from the coarse wavelength demultiplexer, split the power of the optical signals into n portions, and output the n portions of the split optical signals to n combiners respectively.
  • The multiplexer/demultiplexer further includes n combiners, each of which is connected to one output terminal of the AWG and one output terminal of the splitter, for coupling the optical signals having specific wavelengths from the splitter to each of the output branches of the AWG.
  • It can be seen from the above that both the optical signals having specific wavelengths (for example, λb and/or λm and/or other specific wavelengths), which carry the multicast service, and the n channels of the optical signals, which carry the unicast data of each of the ONUs, could be obtained at each of the n output terminals of the multiplexer/demultiplexer shown in Fig. 6, therefore the multiplexer/demultiplexer can be used to the WDM-PON system.
  • It should be understood for a person skilled in the art that other alternative solutions can be used to substitute the multiplexer/demultiplexer in the present embodiment. For example, the functions of the coarse wavelength demultiplexer, the splitter and the combiners may be integrated into a separate AWG, and the multiplexer/demultiplexer may be realized with the coarse wavelength demultiplexer, the splitter, the combiners, a N:N Wavelength Grating Router (WGR), etc..
  • As stated above, each of the n output terminals of the multiplexer/demultiplexer in Fig.6 includes the optical signals having specific wavelengths for carrying the multicast service. However, in some special circumstances, some ONUs in the WDM-PON system may not support the multicast service, and thus it is not necessary to concurrently output the multicast service to all of the output terminals of the multiplexer/demultiplexer. A simplified multiplexer/demultiplexer according to another preferred embodiment of the present invention is provided in Fig.7. The multiplexer/demultiplexer includes a coarse wavelength demultiplexer, which is configured to divide the received optical signals to obtain optical signals having specific wavelengths (for example, λb and/or λm and/or other specific wavelengths) for carrying the multicast service and optical signals for carrying the downstream unicast data of each of the ONUs.
  • The multiplexer/demultiplexer further includes a 1:n AWG, which is configured to divide the optical signals having the wavelengths of λ1∼λn from the coarse wavelength demultiplexer to obtain n channels of optical signals respectively having respective wavelength among the wavelengths of λ1∼λn, and route the optical signals to the n output terminals of the AWG, where n corresponds to the number of the ONUs in the WDM-PON system.
  • The multiplexer/demultiplexer further includes a splitter having a splitting ratio of 1:a. The splitter is configured to perform power allocation on the optical signals having specific wavelengths (for example, λb and/or λm) from the coarse wavelength demultiplexer, split the power of the optical signals into a portions, and output the a portions of the split optical signals to a combiners respectively, where a is a natural number that is larger than or equal to 1 and smaller than n and corresponds to the number of the ONUs supporting the multicast service in the WDM-PON system.
  • The multiplexer/demultiplexer further includes a combiners, each of which is connected to one output terminal of the AWG and one output terminal of the splitter, for coupling the optical signals having specific wavelengths from the splitter to a output branches of the AWG.
  • It can be seen from the above that because the above multiplexer/demultiplexer may concurrently transmit the optical signals carrying the multicast service to each ONU of the WDM-PON system by performing power allocation, it is possible to transmit multicast or broadcast data at a separate wavelength, thereby the bandwidth resource of the system can be greatly saved.
  • Besides the above WDM-PON system and multiplexer/demultiplexer, a method for realizing the multicast service using the WDM-PON system is provided according to another preferred embodiment of the invention. As shown in Fig.8, the method mainly includes the following steps.
  • Step A: the OLT separates, from downstream data from the superior equipment, multicast service data and each channel of downstream unicast data to be transmitted to each of the ONUs in the WDM-PON system.
  • Step B: the OLT carries the multicast service data onto an optical signal having specific wavelength, and carries the downstream unicast date of each of the ONUs onto an optical signal having predetermined downstream wavelength for each of the ONUs respectively.
  • Step C: the optical signal having specific wavelength and the each channel of optical signal carrying the downstream unicast data of each of the ONUs are multiplexed and transmitted to the multiplexer/demultiplexer in the ONU.
  • Step D: the multiplexer/demultiplexer separates, from the received optical signal, the optical signal having specific wavelength and each channel of optical signal carrying the downstream unicast data for each of the ONUs according to wavelength, outputs the optical signal having specific wavelength to all or parts of the ONUs, and outputs each channel of optical signal carrying the downstream unicast data of an ONU to the corresponding ONU.
  • Step E: each of the ONUs in the WDM-PON system separates, from the received optical signal, the optical signal having specific wavelength and the optical signal carrying the downstream unicast data of the ONU itself, performing optical/electrical conversion and demodulation to both of the optical signals to obtain the multicast service data and the downstream unicast data of the ONU itself, and transmits the multicast service data to the lower equipment for further process.
  • Furthermore, as stated above, the OLT can control whether an ONU can receive the multicast service data, by transmitting a corresponding control message to the ONU.
  • The multicast service may be general multicast service, broadcast service, or CATV service. Particularly, for CATV service, the OLT transmits a broadcast control message to the ONU to prohibit the ONU from receiving the CATV broadcast signal or permit the ONU to receive the CATV broadcast signal. After receiving the broadcast control message, if the broadcast control message prohibits the ONU from receiving the CATV broadcast signal, the ONU turns off an optical/electrical converter so as not to receive the CATV broadcast signal, and if the broadcast control message permits the ONU to receive the CATV broadcast signal, the ONU turns on the optical/electrical converter so as to receive the CATV broadcast signal.
  • It can be seen from the above that, through the method, the multicast or broadcast can be realized in the WDM-PON system. Because the multicast service is only transmitted once at a specific wavelength in the WDM-PON system, the problem of the wasting of the bandwidth resource caused by the manner of bandwidth multiple replicas in the related art can be solved. The bandwidth resource of the system can be greatly saved, and the complexity of the OLT can be reduced for there is no need to apply a complex multicast protocol in the OLT.

Claims (25)

  1. A Wavelength Division Multiplexed Passive Optical Network (WDM-PON) system, comprising an Optical Line Terminal (OLT), a multiplexer/demultiplexer and n Optical Network Units (ONUs), where n is a natural number, wherein
    the OLT is configured to carry multicast service data onto an optical signal having specific wavelength and transmit the optical signal to the multiplexer/demultiplexer;
    the multiplexer/demultiplexer is configured to divide optical signals from the OLT to obtain the optical signal having specific wavelength, perform power allocation on the optical signal having the specific wavelength and output optical signals by power allocation to the n ONUs respectively; and
    the n ONUs are configured to receive the multicast service data outputted from corresponding output terminals of the multiplexer/demultiplexer, respectively.
  2. The WDM-PON system according to claim 1, wherein,
    the OLT is further configured to carry downstream unicast data, which are respectively transmitted to the n ONUs, onto optical signals having different wavelengths respectively, multiplex the optical signals having different wavelengths respectively and the optical signal carrying multicast service data into an optical signal, and transmit the multiplexed optical signal to the multiplexer/demultiplexer;
    the multiplexer/demultiplexer is further configured to divide the received optical signal to obtain the optical signals carrying the downstream unicast data of the n ONUs respectively, and selectively output the divided optical signals according to wavelength; and
    the ONUs are further configured to receive their own downstream unicast data outputted from the corresponding output terminals of the multiplexer/demultiplexer.
  3. An Optical Line Terminal (OLT), comprising:
    an OLT downstream processing module, being configured to carry multicast service data onto an optical signal having specific wavelength and output the optical signal.
  4. The OLT according to claim 3, wherein the OLT downstream processing module is further configured to carry downstream unicast data, which are respectively transmitted to the n ONUs, onto optical signals having different wavelengths, multiplex the optical signals having different wavelengths and the optical signal carrying multicast service data into an optical signal, and transmit the multiplexed optical signal.
  5. The OLT according to claim 3 or 4, further comprising a first optical circulator and an OLT upstream processing module,
    wherein the first optical circulator connected to the OLT downstream processing module, the OLT upstream processing module and the multiplexer/demultiplexer, is configured to output the downstream optical signal from the OLT downstream processing module to the multiplexer/demultiplexer, and output an upstream optical signal from the multiplexer/demultiplexer to the OLT upstream processing module; and
    the OLT upstream processing module is configured to receive the upstream optical signal from the first optical circulator and recover upstream data of the n ONUs.
  6. The OLT according to claim 4, wherein the downstream processing module comprises:
    a downstream data separator, configured to separate the downstream service data to obtain multicast service data to be broadcasted or multicasted and n channels of downstream unicast data to be respectively transmitted to the n ONUs;
    a multicast data transmission pre-processing module, configured to receive one or more channels of the multicast service data from the downstream data separator or other transmission paths, and after the multicast service data is processed, output one or more channels of optical signals having specific wavelengths for carrying the multicast service data;
    a primary wide-spectrum laser source, configured to generate a wide-spectrum optical signal;
    a first Array Waveguide Grating (AWG), configured to generate n channels of optical signals having different wavelengths based on the wide-spectrum optical signal outputted from the primary wide-spectrum laser source, so as to provide laser sources with different wavelengths for an optical modulator array;
    an optical modulator array comprising n modulators, configured to modulate the downstream unicast data, which correspond to the n ONUs and come from the downstream data separator, respectively onto n channels of optical signals having different wavelengths generated from the first AWG; and
    a multiplexer, configured to multiplex the optical signals carrying the multicast service data from the multicast service data transmission pre-processing module, and the n channels of optical signals having different wavelengths, which carry the downstream unicast data of the n ONUs, into a single optical signal, and output the single optical signal to the first optical circulator.
  7. The OLT according to claim 6, wherein the multicast service data transmission pre-processing module further comprises:
    at least one laser, being configured to generate at least one channel of optical signal having specific wavelength respectively; and
    at least one modulator, configured to receive the at least one channel of the multicast service data outputted from the downstream data separator, and modulate the multicast service data onto the optical signals having specific wavelengths outputted from the at least one laser.
  8. The OLT according to claim 7, wherein the functions of the lasers and modulators are implemented in a separate equipment.
  9. The OLT according to claim 7 or 8, wherein the multicast service data transmission pre-processing module further comprises:
    one or more optical amplifiers, configured to optically amplify the optical signals having specific wavelengths for carrying the multicast service data.
  10. The OLT according to claim 6, 7, 8 or 9, wherein the multicast service data transmission pre-processing module further comprises an optical amplifier, which is configured to receive a broadcast service optical signal from an superior equipment and optically amplify the broadcast service optical signal.
  11. The OLT according to claim 6, wherein the downstream processing module further comprises an backup wide-spectrum laser source, connected to the first AWG, and configured to provide a backup wide-spectrum optical signal for the AWG when the primary wide-spectrum laser source fails.
  12. The OLT according to claim 5, wherein the OLT upstream processing module further comprises:
    a second AWG, configured to divide n channels of optical signals having different wavelengths from the upstream optical signal outputted from the first optical circulator;
    a Photodiode or Photo Detector (PD) array comprising n PDs, configured to convert one channel of upstream optical signal from the second AWG into an electrical signal respectively; and
    a demodulator array, comprising n demodulators configured to respectively demodulate the electrical signal outputted from the photodiode or PD array and recover the upstream data of n ONU.
  13. A multiplexer/demultiplexer, comprising:
    a coarse wavelength demultiplexer (CWDM), being configured to divide an optical signal having specific wavelength for carrying multicast service data and optical signals having other wavelengths from a received optical signal;
    a splitter with a splitting ratio of 1: a, being configured to perform power allocation on the optical signal carrying multicast service data from the coarse wavelength demultiplexer, split the power of the optical signal into a portions, and output the a portions of the split optical signals to a combiners respectively; and
    a combiners, configured to couple the optical signal having specific wavelength for carrying multicast service data from the splitter to the optical signals having other wavelengths outputted from the coarse wavelength demultiplexer, respectively;
    where a is a natural number that is larger than or equal to 1.
  14. The multiplexer/demultiplexer according to claim 13, further comprising:
    a third 1:n AWG, configured to divide the optical signals having other wavelengths from the coarse wavelength demultiplexer, to obtain n channels of optical signals having different wavelengths, and output a channels of the optical signals having different wavelengths among the n channels of optical signals to the a combiners respectively;
    where n is a natural number that is larger than or equal to a.
  15. The multiplexer/demultiplexer according to claim 14, wherein the functions of the coarse wavelength demultiplexer, the splitter, the combiner and the third AWG are integrated into a separate equipment to implement the function of the multiplexer/demultiplexer.
  16. An Optical Network Unit (ONU), comprising:
    an ONU downstream processing module, configured to process a signal from a corresponding output terminal of a multiplexer/demultiplexer, so as to obtain downstream unicast data corresponding to the ONU itself and multicast service data respectively.
  17. The ONU according to claim 16, further comprising a second optical circulator and an ONU upstream processing module;
    wherein the second optical circulator, connected to the multiplexer/demultiplexer, the ONU downstream processing module and the ONU upstream processing module, is configured to output the downstream optical signal from the multiplexer/demultiplexer to the ONU downstream processing module, and output a upstream optical signal from the ONU upstream processing module to the multiplexer/demultiplexer; and
    the ONU upstream processing module modulates user's upstream data onto an optical signal having corresponding wavelength and outputs the optical signal to the second optical circulator.
  18. The ONU according to claim 16, wherein the ONU downstream processing module comprises:
    a coarse wavelength demultiplexer, configured to divide optical signals having different wavelengths from the downstream optical signal from the second optical circulator;
    a photodiode or optical detector PD array, including at lest two PDs, wherein one of the PDs is configured to convert an optical signal from the coarse wavelength demultiplexer, which carries the downstream unicast data corresponding to the ONU, into an electrical signal, and other PDs are respectively configured to convert one or more channels of optical signals having specific wavelengths from the coarse wavelength demultiplexer, which carry the multicast service data, into electrical signals; and
    a demodulator array, including at least two demodulators, wherein one of the demodulators is configured to demodulate the electrical signal carrying the downstream unicast data for the ONU to obtain the downstream unicast data for the ONU, and other demodulators are respectively configured to demodulate the electrical signals from the other PDs, which carry the multicast service data, to obtain the multicast service data.
  19. The ONU according to claim 16, wherein the ONU upstream processing module comprises a modulator, configured to modulate upstream data of the ONU onto an unmodulated optical signal.
  20. A method for implementing multicast service in a WDM-PON, comprising:
    an OLT separating multicast service data from downstream data, and transmitting the multicast service data, after being carried onto an optical signal having specific wavelength, to a multiplexer/demultiplexer;
    the multiplexer/demultiplexer separating the optical signal having specific wavelength from a received optical signal according to wavelength, and outputting the optical signal having specific wavelength to at least one ONU through performing power allocation; and
    the at least one ONU separating the optical signal having specific wavelength from received optical signals respectively, and obtaining the multicast service data after performing optical/electrical conversion and demodulation on the optical signal having specific wavelength.
  21. The method for implementing multicast service according to claim 20, further comprising:
    the OLT separating downstream unicast data for the at least one ONU from downstream data, modulating the downstream unicast data onto at least one optical signal, multiplexing the at least one optical signal carrying the downstream unicast data with the optical signal carrying multicast service data, and outputting the multiplexed signal to the multiplexer/demultiplexer;
    the multiplexer/demultiplexer separating at least one optical signal carrying downstream unicast data of the ONUs from a received optical signal according to the wavelength, and outputting the separated optical signals to corresponding ONUs respectively; and
    the ONUs separating optical signals carrying their own downstream unicast data from the received optical signals, and obtaining their own downstream unicast data after performing optical-electrical conversion and demodulation on the separated optical signals, respectively.
  22. The method for implementing multicast service according to claim 20 or 21, further comprising:
    the OLT capturing a request for joining a multicast group from an ONU, and implementing the function of a multicast agent in which the OLT performs authentication, determines whether the ONU has the right to receive data of the requested multicast group according to the result of the authentication, and sends a multicast service control message to the ONU according to the result of the determination; and
    the ONU filtering data of the multicast group, which is permitted by the OLT to be received by the ONU, according to the multicast service control message from the OLT, and discarding data of the multicast group, which is not permitted by the OLT to be received by the ONU.
  23. A method for implementing cable television (CATV) broadcasting in a WDM-PON, comprising:
    an OLT receiving an optical signal having specific wavelength, which carries a CATV broadcast signal, from an superior equipment, amplifying the received optical signal with specific wavelength through an optical amplifier, and transmitting the optical signal having specific wavelength, which has been optically amplified, to a multiplexer/demultiplexer;
    the multiplexer/demultiplexer separating, from a received optical signal, the optical signal with specific wavelength carrying the CATV broadcast signal according to wavelength, and outputting the separated optical signal to at least one ONU through performing power allocation; and
    the at least one ONU separating, from received optical signals, the optical signal with specific wavelength carrying the CATV broadcast signal, and after performing optical-electrical conversion, obtaining and transmitting an electrical CATV broadcast signal to a subordinate equipment for further process.
  24. The method for implementing CATV broadcasting according to claim 23, further comprising:
    the OLT multiplexing optical signals carrying downstream unicast data of each of the ONUs and the optical signal having specific wavelength, and outputting the multiplexed signal to the multiplexer/demultiplexer;
    the multiplexer/demultiplexer separating, from the received optical signal, at least one optical signal carrying downstream unicast data of the ONUs according to the wavelength, and outputting the separated optical signals to corresponding ONUs respectively; and
    the ONUs separating optical signals carrying their own downstream unicast data from the received optical signals, obtaining the ONUs' own downstream unicast data after performing optical/electrical conversion and demodulation on the optical signals carrying their own downstream unicast data, and transmitting the downstream unicast data to the subordinate equipment.
  25. The method for implementing CATV broadcasting according to claim 23 or 24, further comprising:
    the OLT sending a broadcast control message to the ONUs as required, wherein the broadcast control message is used to prohibit an ONU from receiving the CATV broadcast signal or permit the ONU to receive the CATV broadcast signal; and
    after the ONU receives the broadcast control message, if the broadcast control message prohibits the ONU from receiving the CATV broadcast signal, the ONU turning off an optical-electrical converter so as not to receive the CATV broadcast signal; and if the broadcast control message permits the ONU to receive the CATV broadcast signal, the ONU turning on the optical-electrical converter so as to receive the CATV broadcast signal.
EP07702163.2A 2006-01-23 2007-01-22 A passive optical network, equipment and method for supporting the multicast service Active EP1981196B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200610001979XA CN101009530B (en) 2006-01-23 2006-01-23 Passive optical network, multiplexing/de-multiplexing device and method supporting the multicast service
PCT/CN2007/000233 WO2007082490A1 (en) 2006-01-23 2007-01-22 A passive optical network, equipment and method for supporting the multicast service

Publications (3)

Publication Number Publication Date
EP1981196A1 true EP1981196A1 (en) 2008-10-15
EP1981196A4 EP1981196A4 (en) 2009-06-03
EP1981196B1 EP1981196B1 (en) 2013-07-03

Family

ID=38287277

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07702163.2A Active EP1981196B1 (en) 2006-01-23 2007-01-22 A passive optical network, equipment and method for supporting the multicast service

Country Status (4)

Country Link
US (1) US20080304830A1 (en)
EP (1) EP1981196B1 (en)
CN (1) CN101009530B (en)
WO (1) WO2007082490A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009062449A1 (en) 2007-11-16 2009-05-22 Huawei Technologies Co., Ltd. A control method, device and system for multicast access in passive optical network
EP2109256A4 (en) * 2007-09-28 2010-01-06 Huawei Tech Co Ltd Pon group broadcast communication system, group broadcast managing method and the corresponding device
CN101547381B (en) * 2009-05-08 2011-08-24 北京科技大学 Multicast RWA method with signal power attenuation limit in all-optical network
CN104730645A (en) * 2015-01-28 2015-06-24 浙江大学 Multiplexer-demultiplexer for mode multiplexing-wavelength division multiplexing hybrid technology
US9559802B1 (en) 2014-09-30 2017-01-31 Google Inc. Optical network remote node for G-PON and WDM-PON
EP3588808A1 (en) * 2018-06-21 2020-01-01 Nokia Solutions and Networks Oy Twdm pon with variable splitting ratio
EP2656527B1 (en) * 2010-12-20 2020-08-12 Telefonaktiebolaget LM Ericsson (publ) A passive optical network arrangement and method

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101114885B (en) * 2007-09-05 2011-07-27 华中科技大学 Wavelength-division and time division multiplex mixing passive optical network system, terminal and signal transmission method
CN101247666B (en) * 2008-03-24 2011-04-20 中兴通讯股份有限公司 Protecting equipment and method based on optical network system
CN101296526B (en) * 2008-06-25 2011-04-13 山东大学 Railway special network communication system based on passive optical network
KR101000518B1 (en) * 2008-12-22 2010-12-14 한국전자통신연구원 Method and apparatus for transmitting multicast or broadcast frame in WDM-PON
US20110097083A1 (en) * 2009-10-07 2011-04-28 Trex Enterprises Corp. Data center optical network
CN101877801A (en) * 2010-05-28 2010-11-03 浙江大学 Optical line terminal of wavelength division multiplexing passive optical network based on semiconductor optical amplifier
EP2538590B1 (en) * 2011-06-20 2013-09-11 NTT DoCoMo, Inc. Communication system and method for transmitting data to one or more groups of nodes in a communication system
EP2731287A4 (en) * 2012-05-23 2014-12-31 Huawei Tech Co Ltd Method, system and device for switching wavelength of multi-wavelength passive optical network (pon)
US8867920B2 (en) 2012-07-24 2014-10-21 International Business Machines Corporation Optical de-multiplexing device
US9366691B2 (en) * 2013-05-02 2016-06-14 Halliburton Energy Services, Inc. Multiplexed fiber optic sensing system and method
US9602311B2 (en) * 2014-02-06 2017-03-21 The Board Of Trustees Of The Leland Stanford Junior University Dual-mode network
JP6427992B2 (en) * 2014-06-30 2018-11-28 富士通株式会社 Optical transmission system, transmitter, receiver, and optical transmission method
US9806844B2 (en) * 2014-11-10 2017-10-31 Perfectvision Manufacturing, Inc. Electromagnetic signal transport and distribution system
US10250353B2 (en) 2014-11-10 2019-04-02 Perfectvision Manufacturing, Inc. Electromagnetic signal transport and distribution systems
KR20160107866A (en) * 2015-03-06 2016-09-19 한국전자통신연구원 Central base station capable of allocating multiple wavelengths dynamically
CN104837079B (en) * 2015-04-15 2018-08-28 北京邮电大学 Multi-wavelength multicast apparatus in Wave division multiplexing passive optical network and method
US9749080B2 (en) * 2015-11-11 2017-08-29 Google Inc. TWDM passive network with extended reach and capacity
CN107666362B (en) * 2016-07-28 2020-10-27 全球能源互联网研究院 Power communication multi-service isolation access system and access method
US10200144B1 (en) 2017-09-15 2019-02-05 Nokia Of America Corporation Communication system for connecting network hosts
CN110308522A (en) * 2019-07-09 2019-10-08 中山市标致电子科技有限公司 A kind of coarse wavelength division multiplexer device
CN112217593B (en) * 2019-07-12 2023-01-13 中国移动通信有限公司研究院 Management control method and equipment for new forwarding network
KR102491712B1 (en) * 2022-07-07 2023-01-27 (주)엠이엘 텔레콤 Optical fiber connectivity tester
US20240072897A1 (en) * 2022-08-31 2024-02-29 Panduit Corp. Apparatus and methods for fiber optic bi-directional local area networks

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000074278A1 (en) * 1999-05-28 2000-12-07 Advanced Fibre Communications Wdm passive optical network with broadcast overlay
US20040184806A1 (en) * 2003-03-17 2004-09-23 Ki-Cheol Lee Wavelength division multiplexing-passive optical network capable of integrating broadcast and communication services
EP1608106A2 (en) * 2004-06-01 2005-12-21 Alcatel System and method for providing packetized video over an optical network

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5440416A (en) * 1993-02-24 1995-08-08 At&T Corp. Optical network comprising a compact wavelength-dividing component
US5926298A (en) * 1996-08-30 1999-07-20 Lucent Technologies Inc. Optical multiplexer/demultiplexer having a broadcast port
KR100367086B1 (en) * 2000-12-23 2003-01-09 한국전자통신연구원 Optical Network Unit For The Services Of Voice And Broadband Data
KR100496710B1 (en) * 2002-01-21 2005-06-28 노베라옵틱스코리아 주식회사 Bi-directional wavelength-division-multiplexing passive optical network utilizing wavelength-locked light sources by injected incoherent light
KR20050050615A (en) * 2002-04-23 2005-05-31 알자 코포레이션 Transdermal analgesic systems with reduced abuse potential
KR20040026177A (en) * 2002-09-23 2004-03-30 삼성전자주식회사 Optical subscribing network for receiving broadcasting/communication signals
US7327771B2 (en) * 2003-10-21 2008-02-05 Electronics And Telecommunications Research Institute WDM-PON system with optical wavelength alignment function
US20050129404A1 (en) * 2003-12-10 2005-06-16 Kim Byoung W. Apparatus for providing broadcasting service through overlay structure in WDM-PON
CN100461654C (en) * 2003-12-12 2009-02-11 武汉华工飞腾光子科技有限公司 Ethernet passive optical network based on Wavelength Division Multiple Access and data transmission method thereof
KR100605925B1 (en) * 2004-01-27 2006-08-01 삼성전자주식회사 Wavelength-division-multiplexed passive optical network
KR100570842B1 (en) * 2004-12-13 2006-04-13 한국전자통신연구원 Dynamic multicasting group management and service wavelength allocation method for communication and broadcasting converged service in wdm-pons
KR100703388B1 (en) * 2004-12-29 2007-04-03 삼성전자주식회사 Optical transceiver and passive optical network using the same
US7522838B2 (en) * 2005-10-20 2009-04-21 Fujitsu Limited Distribution components for a wavelength-sharing network
US7603036B2 (en) * 2006-01-06 2009-10-13 Fujitsu Limited System and method for managing network components in a hybrid passive optical network

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000074278A1 (en) * 1999-05-28 2000-12-07 Advanced Fibre Communications Wdm passive optical network with broadcast overlay
US20040184806A1 (en) * 2003-03-17 2004-09-23 Ki-Cheol Lee Wavelength division multiplexing-passive optical network capable of integrating broadcast and communication services
EP1608106A2 (en) * 2004-06-01 2005-12-21 Alcatel System and method for providing packetized video over an optical network

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
NAMUK KIM ET AL: "Advanced multicast service scheduling mechanism with IGMP snooping in WDM-PON" ADVANCED COMMUNICATION TECHNOLOGY, 2005, ICACT 2005. THE 7TH INTERNATI ONAL CONFERENCE ON PHOENIX PARK, KOREA FEB. 21-23, 2005, PISCATAWAY, NJ, USA,IEEE, vol. 1, 21 February 2005 (2005-02-21), pages 298-302, XP010813620 ISBN: 978-89-5519-123-3 *
See also references of WO2007082490A1 *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2109256A4 (en) * 2007-09-28 2010-01-06 Huawei Tech Co Ltd Pon group broadcast communication system, group broadcast managing method and the corresponding device
WO2009062449A1 (en) 2007-11-16 2009-05-22 Huawei Technologies Co., Ltd. A control method, device and system for multicast access in passive optical network
EP2091187A4 (en) * 2007-11-16 2009-12-02 Huawei Tech Co Ltd A control method, device and system for multicast access in passive optical network
CN101547381B (en) * 2009-05-08 2011-08-24 北京科技大学 Multicast RWA method with signal power attenuation limit in all-optical network
EP2656527B1 (en) * 2010-12-20 2020-08-12 Telefonaktiebolaget LM Ericsson (publ) A passive optical network arrangement and method
US9559802B1 (en) 2014-09-30 2017-01-31 Google Inc. Optical network remote node for G-PON and WDM-PON
CN104730645A (en) * 2015-01-28 2015-06-24 浙江大学 Multiplexer-demultiplexer for mode multiplexing-wavelength division multiplexing hybrid technology
EP3588808A1 (en) * 2018-06-21 2020-01-01 Nokia Solutions and Networks Oy Twdm pon with variable splitting ratio

Also Published As

Publication number Publication date
WO2007082490A1 (en) 2007-07-26
EP1981196B1 (en) 2013-07-03
EP1981196A4 (en) 2009-06-03
CN101009530A (en) 2007-08-01
US20080304830A1 (en) 2008-12-11
CN101009530B (en) 2012-02-15

Similar Documents

Publication Publication Date Title
EP1981196B1 (en) A passive optical network, equipment and method for supporting the multicast service
KR100605855B1 (en) Switched broadcasting FTTH system using single fiber
CN101047464B (en) Controlled multicast method and system for wave complex optical network
US8554078B2 (en) Passive optical network with plural optical line terminals
EP2209228B1 (en) An optical line terminal, a remote node unit, an optical transimission method and system thereof
CN101119163B (en) WDM-PON method, system and optical line terminal for implementing multicast service
EP2122878B1 (en) Backward compatible pon coexistence
KR100975882B1 (en) Time division multiple access over wavelength division multiplexed passive optical network
WO2007071154A1 (en) A wavelength division multiplexing passive optical network and its implement method
CN101238654B (en) Wave division multiplexing passive optical network system
JP2004282749A (en) Passive optical subscriber network of broadcast/communication integrable wavelength division multiplex system
CN101098206A (en) Passive optical network system and light path processing method
US20100021164A1 (en) Wdm pon rf/video broadcast overlay
JP2004096737A (en) Broadcast/communication integrated passive optical network system
CN101068129B (en) Method for realizing group broadcasting service in WDM-PON , system thereof and OLT
WO2007143945A1 (en) Wavelength routing module, system and method therewith
KR20050002467A (en) Ethernet Passive Optical Network for Convergence of Broadcasting and Telecommunication
JP7480309B2 (en) Optical line terminal, optical network unit, and optical communication system
KR100990780B1 (en) Wavelength division multiplexing - passive optical network system
KR100746467B1 (en) WDM-PON system for providing RF video service and its signal transmission method
KR101231927B1 (en) Bidirectional WDM-PON system using single channel and bidirectional signal transmitting method thereof
JPWO2007083384A1 (en) Unidirectional transmission signal distribution method, station side apparatus and subscriber premises side apparatus in passive optical network system
Nerkar Narendra et al. Design of AWG-based WDM-PON architecture With multicast capability

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20080804

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

A4 Supplementary search report drawn up and despatched

Effective date: 20090508

17Q First examination report despatched

Effective date: 20110504

DAX Request for extension of the european patent (deleted)
REG Reference to a national code

Ref country code: DE

Ref legal event code: R079

Ref document number: 602007031372

Country of ref document: DE

Free format text: PREVIOUS MAIN CLASS: H04J0014020000

Ipc: H04B0010250000

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RIC1 Information provided on ipc code assigned before grant

Ipc: H04J 14/02 20060101ALI20130129BHEP

Ipc: H04B 10/25 20130101AFI20130129BHEP

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 620256

Country of ref document: AT

Kind code of ref document: T

Effective date: 20130715

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602007031372

Country of ref document: DE

Effective date: 20130829

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 620256

Country of ref document: AT

Kind code of ref document: T

Effective date: 20130703

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20130703

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130626

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20131103

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20131104

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20131014

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20131004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

26N No opposition filed

Effective date: 20140404

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602007031372

Country of ref document: DE

Effective date: 20140404

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: LU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140122

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140131

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140131

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20140122

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20130703

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20070122

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 11

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20231130

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20231212

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20231205

Year of fee payment: 18